According to Oracle's security announcement, the patch pack addresses 40 different vulnerabilities. All update levels of Java SE 5, 6, and 7 are affected by the flaws, as are all versions of JavaFX.

Of the 40 bugs, all but three are remotely exploitable over a network without the need for a username or password.

Yes, that's bad. Oracle ranks the severity of its flaws using the Common Vulnerability Scoring System (CVSS), and the top-ranked bug in this particular update rates a 10.0 – the highest possible score.

Oracle ordinarily releases Critical Patch Updates four times a year on a set schedule, but this will already be the fourth such update issued in 2013. The first shipped on February 1, but Oracle reissued it later in the month with additional fixes. It also scheduled another, previously unplanned update for April.

Each of those earlier updates contained upward of 40 fixes, and each similarly addressed flaws that rated 10.0 on the CVSS severity scale.

Oracle has not yet disclosed which vulnerabilities will be patched by the June update, but previous Critical Patch Updates have patched vulnerabilities in a wide range of Java APIs and subsystems. These flaws could potentially affect a whole host of Java software and were not limited to programs running via the Java browser plugin, as has been the case with some previous Java exploits.

Oracle plans to release its latest Java SE Critical Patch Update on June 18, 2013. After that, the next update is currently scheduled for October 15. ®